Shattering revelations can often be the garland round the neck of the well-made thriller.
But when they occur in five-second flashbacks, you'd better be sharp to keep up.
To say more would be going unfairly into the ingenious plot of this Francis Ford Coppola film, which features Gene Hackman as a professional eavesdropper haunted by the time his 'bugging' cost the lives of three people and terrified that it's happening again.
Hackman is excellent as the 'tapper', and the mood of his loneliness and isolation is well established.
But don't blink during the last reel.
A pre-stardom Teri Garr and Harrison Ford appear in minor roles.